password protection for vhost

I have a very simple problem but cannot figure it out. I would like to password protect a vhost. This vhost is instaniated. I don't want to do it with .htaccess. I have created the realm and the context, but I always get "Authentication failed with user xxx". This is the relevant configuration:

I have now tried to do the same with .htaccess: Does not work either with the same users file. But if I create a .htpasswd with the password unencrypted it works. So it apparently has to do with the users file. I have created the users file normally using the lsws admin and it looks good. The only thing that's new to me is a ":" at the end of the user entry (after the password).

Thank you. I already tried "user xxx", but did not work. Also the lsws documentation says that "required" can be left empty and then every user would be valid (the same as "valid-user").
The users file exists and contains the correct user.

can you try to install standard version on the same vhost but in another location instead of default /usr/local/lsws. then access the homepage, there is a demo page for Authentication, see if that works for you. the line read:
"Authentication: Password protected content, use user name: test, password: test123"